Mobile communication devices—such as smart phones—may be single radio long term evolution (SRLTE) communication devices in which a single radio frequency resource (RF resource) supports both data and voice calls in a mobile telephony network (e.g., Code Division Multiple Access (CDMA) networks or Global System for Mobile Communications (GSM) Enhanced Data Rate for GSM Evolution (EDGE) Radio Access Network (GERAN) networks).
When an incoming call is available for an SRLTE communication device, the mobile telephony network enters a Mobile Switching Center (MSC)-Sub paging scenario in which the network attempts to notify the SRLTE communication device of the incoming call by sending Mobile Termination (MT) paging messages to the SRLTE communication device on all configured paging channels for the serving base station (BS) for the SRLTE communication device registered with the network, as well as through all paging channels for the base stations neighboring the serving base station. When the SRLTE communication device receives the MT paging message via one of the paging channels, the SRLTE communication device responds with an MT page response message indicating that the MT call can be established.
However, the process of responding to a received MT paging message is not instantaneous. Delays result from processing the MT paging message and delays in reconfiguring the RF resource of the SRLTE communication device. For example, when the SRLTE communication device is conducting a data call at the time a MT paging message is received, an Extended Service Request (ESR) procedure for the data service may need to be completed before an MT page response can be sent by the SRLTE communication device.
During delays between receiving MT paging messages and being able to send MT page response messages, the SRLTE communication device may have handed off from the serving base station to another new base station due to movement of the device and/or changing network conditions. The paging channel in the new base station may be different from the paging channel in the previous serving base station on which the MT paging message was received. In current systems, prior to sending an MT page response, the SRLTE communication device will check the current paging channel being used against the paging channel on which the MT paging message was received. In response to determining that there is a mismatch between the current paging channel and the paging channel on which the MT paging message was received, the SRLTE communication device will drop the MT paging message. Dropping the MT paging message causes the SRLTE communication device to not send a MT page response and leads to a delay in establishing the call or a preemptive drop of the call.